“Keeping these insect pests out of the United States is of grave concern for U.S. Customs and Border Protection, and our agriculture specialists take their job very seriously,” Susan Stranieri, CBP Port Director for the Area Port of Philadelphia, said in a press release. “Holding the line against destructive insects at our nation’s borders protects America’s varied agricultural industries, and saves our nation’s economy the expense associated with eradicating and recovering from new invasive species.”

Because many bugs can be dangerous to humans, livestock and ecosystems, the U.S. has stringent rules on the types of bugs allowed into the country.

One of the recent seizures involved a seed bug that came from a shipment in Costa Rica. It poses serious risks to crops, shrubs, grains and trees.